This study to assess the relationships among social support, stress, personality, and physical health between young adulthood and late middle age involves use of longitudinal data collected over the course of 50 years from a large and representative sample of persons to achieve four specific aims: 1) Assessment at each of four ages (30, 40, 50 and 60 years) of the relations between physical health and stress, social support and personality; 2) Assessment of the interrelationship among social support, stress and health with special focus on the question of whether or not social support has a direct effect on health; 3) Assessment of the relationship across adjacent age periods between physical health and stress, social support and personality; and 4) Assessment of the interrelationship among personality, stress and health with particular attention to possible variation across personality types in vulnerability to the effects of stress on health. Measures are derived from data collected from approximately 200 persons studied intensively from the time of their birth or entry to junior high school by an interdisciplinary group of behavioral and medical scientists. Multiple regression analyses of the data are performed to clarify the relations among the study variables in order to further our understanding of the nature of psycho-social influences on health through the adult years.